Typical deck has a 33% win rate after Farm 2 + the 3 easy mages.

TARGET: 42% after 10 minutes

10 minutes of A-TECs: 49%
If you only win 3rd MM: 44%
10 minutes of Meadow: 58%
If you only win 1st MBD: 54%

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With weak deck (20%): 

Target: 26% after 10 minutes

10 minutes of A-TECs: 41%
If you only win 3rd MM: 32%
10 minutes of Meadow: 47%
If you only win 1st MBD: 42%

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With strong deck (39%):

TARGET: 50% after 10 minutes

10 minutes of A-TECs: 51%
If you only win 3rd MM: 49%
10 minutes of Meadow: 63%
If you only win 1st MBD: 58%

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SUMMARY: It's almost always faster on average to farm until your deck is godly (even if farms are awkward), but in 1-on-1 races against good opponents, you will likely need to cut some farms short to maximize your chance of winning the race.